An optical fiber is formed from silica glass, and includes a core, a first cladding which surrounds the core and has a refractive index lower than the refractive index of the core, and a second cladding which surrounds the first cladding and has a refractive index that is lower than the refractive index of the core and higher than the refractive index of the first cladding. The second cladding is divided into an inner region that is in contact with the first cladding and an outer region which surrounds the inner region and has a thickness that is half the thickness of the second cladding or less, while being 5 m or more. The residual stress in at least a part of the outer region is a compressive stress.

A manufacturing apparatus of a porous glass base material for optical fiber includes: a liquid mass flow controller for controlling a flow rate of a raw material liquid of an organic siloxane; a vaporizer for mixing the raw material liquid and a carrier gas to vaporize the raw material liquid to form a mixed gas in which a raw material gas and the carrier gas are mixed; a raw material liquid nozzle for ejecting the raw material liquid into the vaporizer; a carrier gas supply pipe for supplying the carrier gas into the vaporizer; a raw material liquid pipe for introducing the raw material liquid into the raw material liquid nozzle; a burner for combusting the mixed gas together with a combustible gas and a combustion supporting gas to produce SiO.sub.2 fine particles; a mixed gas pipe; an open/close valve; and a purge gas supply pipe.

Disclosed is a photosensitive resin composition for an optical waveguide containing a resin component and a photoacid generator. In the photosensitive resin composition, the resin component is constituted of an epoxy resin component containing both an aromatic epoxy resin and an aliphatic epoxy resin, and the content of the aromatic epoxy resin is 55 wt. % or more and less than 80 wt. % of the entirety of the epoxy resin component and the content of the aliphatic epoxy resin is more than 20 wt. % and 45 wt. % or less of the entirety of the epoxy resin component. Accordingly, for example, when a core layer of an optical waveguide is formed using the disclosed photosensitive resin composition for an optical waveguide, a core layer of an optical waveguide having satisfactorily low tackiness and high transparency while maintaining satisfactory roll-to-roll compatibility and a high resolution patterning property can be formed.

A plastic optical fiber for a medical device lighting decreases the cost of a lens and simplify the design of a lighting apparatus, wherein the plastic optical fiber for a medical device includes a core composed of a (co)polymer containing methyl methacrylate as a main component and is characterized by including a cladding material composed of a copolymer having a fluorine weight composition ratio of 60 to 74%, and by having a theoretical numerical aperture, NA, of 0.48 to 0.65 and, thus, the plastic optical fiber has a high numerical aperture and also has excellent translucency and flexibility.

A plastic optical fiber for a medical device lighting decreases the cost of a lens and simplify the design of a lighting apparatus, wherein the plastic optical fiber for a medical device includes a core composed of a (co)polymer containing methyl methacrylate as a main component and is characterized by including a cladding material composed of a copolymer having a fluorine weight composition ratio of 60 to 74%, and by having a theoretical numerical aperture, NA, of 0.48 to 0.65 and, thus, the plastic optical fiber has a high numerical aperture and also has excellent translucency and flexibility.

There is provided an optical waveguide laminate in which an organic base material layer comprised of an insulation layer and a coverlay is laminated to one surface of an optical waveguide and in which a portion of the organic base material layer is lacking so that the optical waveguide is uncovered. Inequalities P70% and PQ25% are satisfied where P is the laser light transmittance in at least a portion of the optical waveguide, the laser light having a predetermined wavelength range, and Q is the laser light transmittance of at least a portion of the organic base material layer. In this optical waveguide laminate, the organic base material layer laminated to the optical waveguide is elaborately removed without being impaired or thermally damaged by laser machining.

There is provided an optical waveguide laminate in which an organic base material layer comprised of an insulation layer and a coverlay is laminated to one surface of an optical waveguide and in which a portion of the organic base material layer is lacking so that the optical waveguide is uncovered. Inequalities P70% and PQ25% are satisfied where P is the laser light transmittance in at least a portion of the optical waveguide, the laser light having a predetermined wavelength range, and Q is the laser light transmittance of at least a portion of the organic base material layer. In this optical waveguide laminate, the organic base material layer laminated to the optical waveguide is elaborately removed without being impaired or thermally damaged by laser machining.

An optical waveguide provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

An optical waveguide provided and includes: a core forming layer with a high refractive index; and a first clad layer with a low refractive index, bonded to a first main surface of the core forming layer. The core forming layer is provided in its plane direction with a core portion, lateral clad portions each having one side adjacent to a corresponding side of the core portion, and high refractive index portions each adjacent to the other side of a corresponding one of the lateral clad portions. The core portion is provided in its plane direction with a central region, and GI regions in each of which a refractive index continuously decreases from the central region toward an interface with the corresponding one of the lateral clad portions. The lateral clad portions each include a region having a constant refractive index.

This invention relates to a method of preparing a planar optical waveguide assembly comprising the steps of: (i) applying a curable silicone composition to a surface of a substrate to form a film; (ii) exposing the product of step (i) to ultraviolet light to form a lower clad layer; (iii) applying a photo sensitive composition on top of the lower clad layer to form a core layer on top of the lower clad layer, wherein the photo sensitive composition comprises: (A) a siloxane resin composition comprising 0 to 95 mole present of R.sup.1SiO.sub.3/2 siloxane units, 0 to 95 mole percent of R.sup.2SiO.sub.3/2 siloxane units, and 1 to 99.9 mole percent of (R.sup.3O).sub.bSiO.sub.(4-b)/2 siloxane units wherein R.sup.1 is hydrogen, an alkyl group containing 1 to 20 carbon atoms, an aromatic group containing 1 to 20 carbon atoms, or an epoxy functional group, R.sup.2 is a fluoroalkyl group containing 1 to 20 carbon atoms, R.sup.3 is independently selected from the group consisting of branched alkyl groups containing 3 to 30 carbon atoms, b has a value of 1 to 3, and wherein the siloxane resin composition the siloxane resin contains a molar ratio of R.sup.1SiO.sub.3/2+R.sup.2SiO.sub.3/2 siloxane units to (R.sup.3O).sub.bSiO.sub.(4-b)/2 siloxane units of 1:99 to 99:1 and wherein the sum of R.sup.1SiO.sub.3/2 siloxane units, R.sup.2SiO.sub.3/2 siloxane units, and (R.sup.3O).sub.bSiO.sub.(4-b)/2 siloxane units is at least 5 mole percent of the total siloxane units in the resin composition; (B) a photo acid generator (PAG); and (C) an organic solvent; (iv) exposing the product of step (iii) to ultraviolet light through a mask to selectively irradiate the core layer to create both exposed and unexposed regions to form a patterned waveguide structure; (v) heating the patterned waveguide structure of step (iv); (vi) applying a developing solvent to the product of step (v); (vii) applying a curable silicone composition onto the top layer of the product of step (vi) wherein the curable silicone composition has a lower refractive index than the curable silicone composition of step (i); (viii) exposing the product of step (vii) to ultraviolet light; (viv) heating the product of step (viii) to form a planar optical waveguide assembly.